Book Image

Hands-On Functional Programming with TypeScript

By : Remo H. Jansen
Book Image

Hands-On Functional Programming with TypeScript

By: Remo H. Jansen

Overview of this book

Functional programming is a powerful programming paradigm that can help you to write better code. However, learning functional programming can be complicated, and the existing literature is often too complex for beginners. This book is an approachable introduction to functional programming and reactive programming with TypeScript for readers without previous experience in functional programming with JavaScript, TypeScript , or any other programming language. The book will help you understand the pros, cons, and core principles of functional programming in TypeScript. It will explain higher order functions, referential transparency, functional composition, and monads with the help of effective code examples. Using TypeScript as a functional programming language, you’ll also be able to brush up on your knowledge of applying functional programming techniques, including currying, laziness, and immutability, to real-world scenarios. By the end of this book, you will be confident when it comes to using core functional and reactive programming techniques to help you build effective applications with TypeScript.
Table of Contents (14 chapters)
5
The Runtime – Closures and Prototypes

Functional Programming Fundamentals

JavaScript has been a multi-paradigm programming language since its inception back in 1995. It allows us to take advantage of an object-oriented programming (OOP) style along with a functional programming style. The same can be said of TypeScript. However, for functional programming, TypeScript is even better suited than JavaScript because, as we will learn in this chapter, static type systems and type inference are both very important features in functional programming languages such as the ML family of programming languages, for example.

The JavaScript and TypeScript ecosystems have experienced a significant increase in interest in functional programming over the last few years. I believe that this increase in interest can be attributed to the success of React. React is a library developed by Facebook for building user interfaces, and it is highly influenced by some core functional programming concepts.

In this chapter, we will focus on learning some of the most basic functional programming concepts and principles.

In this chapter, you will learn about the following:

  • The main characteristics of functional programming
  • The main benefits of functional programming
  • Pure functions
  • side-effects
  • Immutability
  • Function arity
  • Higher-order functions
  • Laziness